R.O.W. By the Numbers

Minnesota may be the land of 10,000 lakes, but ever since Tim Thompson arrived at Lake Region Electric Cooperative (LREC) in the west-central part of the state, he’s been concerned with another number: 148,593.

That’s the figure a vegetation management consulting company came up with in 2009 after an initial assessment of trees growing, or threatening to grow, into the Pelican Rapids-based co-op’s lines. For Thompson, who’d started as the CEO a little more than a year earlier, it was an eye-opener.

“That is nearly 40 trees per mile of power line across the entire LREC system,” Thompson wrote in a case study for ACRT Inc., the consulting company that did the assessment.

The assessment concluded that limbs were overhanging lines, or would grow over lines within five years, every 132 feet along 5,700 miles of cable serving the co-op’s 27,000 consumers.

Those calculations sent up a red flag, of course, for existing and potential outage and service-quality problems. But Thompson remembers another worry creeping in as he toured his new service territory eight years ago: About 10 percent of Minnesota’s famous lakes lie within LREC’s service territory, and summer homes and cabins line those shores. His tour took him right alongside those leafy retreats.

“I was walking under the line, and when I looked up, I could see it going right through the trees,” Thompson recalls. “Then I look over toward the lake, and what do I see? All these kids, swimming, running around, playing catch. And then I looked back up at the line. Now, did you ever climb a tree when you were a kid? It just looked like a huge liability, and it was really motivating to solve the problem.”

‘Start the Chainsaws’

For Thompson, the lesson was clear: LREC needed to get a better handle on controlling the tens of thousands of trees flanking its lines. Prior to his arrival, he says, the co-op had been spending around half a million dollars a year clearing limbs and falls, mostly in response to outage calls and members concerned about low-hanging branches.

“We just didn’t have an adequate plan,” he says. “It was underfunded, and therefore we never budgeted enough. We had stacks of service orders for limbs that needed trimming, and we’d have consumers coming in worried about trees on their lines.”

What was needed, Thompson concluded, was a more comprehensive, numbers-based approach to keeping the trees in check.

To begin with, he opted for the threat assessment. But the cost of simply counting trees ran into some resistance. “People said, ‘Tim, let’s just take that money and start cutting trees. Let’s start the chainsaws and get going.’”

Thompson countered that before the co-op could develop a sound tree-trimming plan, it needed to understand the scope of the work. And the result was the initial assessment of 148,593 threatening trees.

The next step was to figure out where the most pressing dangers were so LREC could send its contract cutting crews to the right circuits and stretches of line. That would allow the work to proceed far more efficiently than responding call-by-call to outages or consumer concerns.

“That’s important,” Thompson says, “because if you can get to the trees before they get into the line, the cost goes way down.”

LREC worked with ACRT on one of its early pilot projects to develop a tree-trimming model the company calls “Arborcision.” The model laid out an orderly plan of attack on overhanging limbs, both those that were in the lines right then and those that would reach into the lines soon.

“Maybe the best way to explain it is an analogy,” Thompson says. “Co-ops for decades have used engineering models to make their construction work plans. Well, we didn’t have a very sophisticated way to put together our vegetation management plan. With Arborcision, we’ve collected a lot of representative data on what trees are there, how close they are to the right-of-way, how fast they grow.”

The plan lays out a coordinated, phased approach to protecting co-op lines from overhanging limbs, circuit by circuit and substation by substation.

“Let’s say there’s four circuits coming off a substation,” Thompson says. “The first time around, we had to do all four. But now we can predict, using the model, that we only have to do circuits two and three but not one and four. It’s a real valuable tool.”

Staff Tree Expert

Chris Byrnes, LREC’s system arborist, helped put that plan together back in 2009. He was an ACRT arborist then. The tree assessment—the study that led to the trimming management plan—was based on about 1,000 samples taken along the co-op’s rights-of-way, he says.

“It spins out what we’ve got along the lines, it has all the metrics of the trees along the lines, and it projects them about five years out,” Byrnes says. The resulting management model “goes down to the circuit level. Most of our circuits are around 40 or 50 miles of line. If a circuit has a lot of trees that are fast growing, it will kind of bump that circuit up on the plan.

“Right now, I have a list that says, ‘This circuit has to be taken care of right now,’ and then I just work down the list,” he says. “But last year, we had a lot of danger trees to deal with, so the plan would rerun the algorithm and tell me how much that change will cost.”

In the meantime, besides running Arborcision and keeping the contractors on the co-op’s tree-trimming plan, Byrnes has another important task as system arborist: responding to, and working with, members whose trees need attention or may need attention sometime soon.

“Most of our work is routine maintenance now,” he says. “I don’t get to talk to every single member, but when one has concerns or questions, I can point to the plan and explain what we’re doing and why we’re doing it. And I try to tell them what it’s going to look like when we’re done.”

“Those call-ins cost about three times as much because there’s no concentration of the work,” he says. “So we might try to put it off a bit. Unless it’s a danger tree that needs to be dealt with immediately, I’ll tell them about the plan and say that we’ll be getting to that tree in a year or two.”

A visit from the co-op’s system arborist makes a strong impression on members, Thompson says.

“You can just imagine how different it is for the member to have our new system arborist, a tree expert if you will, come in and talk to them,” he says. “And our guy Chris is really good at that.”

‘No Longer a Guess’

In the first few years after LREC developed its plan, its tree-trimming budget took a substantial jump. After all, it had nearly 150,000 threatening trees to trim.

But that budget item has come down now, settling in about where the co-op was when it first started assessing, planning, and measuring its tree-trimming progress. Some other figures, compiled by LREC and ACRT, suggest how the cost reduction has come about:

Average trees per mile of line dropped from 40 in 2009 to six in 2014.

Outages caused by trees, calculated at 60 to 70 percent in 2009, was 30 to 40 percent five years later.

The trimming contractor’s crews spent 10 percent of their time running from hot spot to hot spot in 2014 as opposed to 2009, when 50 percent of the crews’ time was spent responding to calls.

Finally, there’s Thompson’s favorite: the comparison of overall outages from 2004 to 2016. “Our outages over that 12-year period have decreased 61 percent,” the CEO says. “That’s huge.”

And all of the figures come together when he presents the budget to his board.

“We’re spending a lot of money on tree clearing, and we want to make sure we’re optimizing that spend. All I know is that when I’m in the boardroom and we’re in the budget process, it’s no longer a guess; it’s a pretty scientific number.”

Members have definitely noticed, he adds, from the farmers who run big operations in the fertile Red River Valley on the western fringes of the co-op’s territory to those seasonal members who spend weeks every summer on the wooded lakeshores.

“We have lake association meetings that we attend, with probably 60 or 70 people showing up,” Thompson says. “We were asked to speak at those meetings, and we brought pictures of what we’d done. I don’t mean to brag, but they clapped after our presentation. The improvements are real, they’re visible, they’re noticeable.”

Most of all, they’re noticeable in lines that are safer for crews to work on and for kids at play during a summertime visit to the lake.

“From a safety and reliability standpoint, it’s huge,” he says. “Safety and reliability are the most important things.”